Okay, now we have it's identity sorted (well sort of!), I think I have decided what to do.
Given the mowers lack of identifying features and therefore lack of collectability I will restore the mower to a useable and presentable condition without worrying about authenticity.
As I don't know how well it will mow because of the twisted chassis I don't want to spend too much money on it so this is what I plan:
1) Strip down to chassis but leave soleplate and roller attached and repair broken rail as per Jarrad's suggestion. Jarrad, you mentioned you have the equipment and you seem to know what you're talking about so would you be keen to have a go at this for me?
2) While the engine is off, determine the condition of crankshaft and keyway etc.... and therefore determine the servicability of the engine. If it seems okay then I will give the fuel tank and carby a good clean and service and see how it runs. If not I will source a new engine, probably a 3.5HP B&S from eBay for $275.
3) When the chassis is repaired I will have the blades sharpened and then put it all back together with a new clutch assembly.
4) At this point I will see how well it cuts. If it cuts well, I will strip it back down and sand/prime and paint and then replace all sprockets, chains and whatever else needs replacing. I will then have a functional mower that should last for years. If on the other hand the cut is no good due to the twist in the chassis, I will then have to see what else can be done to sort out the twist.
What do you think? I know it's not ideal, but considering the current condition and missing ID I think this is probably the wisest think to do.
Steve